SPACE Cotton

The ability of astronauts to grow plants in low gravity has always been lost in space. But cotton and its unique cell structure could hold the force that allows space shuttle crews, and eventually International Space Station inhabitants, to boldly grow what they've never grown before.

USDA scientists have teamed with NASA to perform new cotton research aboard an upcoming shuttle flight. They're hopeful that this research could lead to methods of growing food for long-term space missions, and even improve fiber quality for farmers “back on earth.”

The inability to grow plants in space has been a consistent problem. Low gravity is one of the main obstacles, along with the lack of light. And Barbara Triplett, plant physiologist for the USDA-ARS Southern Regional Research Center in New Orleans, says that should not hamper space-cotton growth. She sees the studies as possibly the missing link in successful plant growth in tomorrow land.

Triplett, who approached NASA about conducting the experiment, is eyeing a target launch date for her experiments of between April and August. She won't be on the flight, but will be involved in least two simulation runs at the Kennedy Space Center in Florida prior to the mission.

“NASA is interested in our experiments as part of its long-range plans to enhance the nutritional needs of astronauts in future missions,” says Triplett. “NASA scientists are also interested in finding out why and how the microgravity environment affects plant growth in a negative way.”

Her research will follow previous studies by both the U.S. and Russian space programs. These studies showed that plants germinated in low gravity developed altered cell wall structure. “But since the cotton fiber cell walls are not required for physical support of any plant organ, cotton should be well suited for development in a space environment,” she says. “It's a perfect model for plant cell research at microgravity.”

Triplett sees the studies as a unique opportunity to gain more knowledge of how plants grow and how fiber is developed.

The cultures will be housed in a portion of the space shuttle where temperatures are 68-78°, ideal for fiber development. Carbon dioxide exhaled by astronauts will also benefit culture growth. “Since light is not critical for fiber development, we can get the fiber to grow in absolute darkness inside special canisters aboard the shuttle,” says Triplett.

After 10 days of growth in space, astronauts will place the cultures into a freezer, where they will remain frozen until Triplett's team removes them for analysis.

She will read the genetic code of genes from the low-gravity-grown fiber and compare it to fibers produced in her laboratory. From that analysis, Triplett will identify genes involved in fiber growth and development. “We will see which of the some 25,000 genes are most important for the initiation of fiber growth and fiber elongation,” she says.

Triplett stresses that the growth of cotton fiber cells is not unlike how all plant cells grow. “The results of these tests could be far reaching,” she says. “We will have a better idea of how to improve plant and crop growth, a better idea why apples are a certain size.”